Fluorene belongs to the polycyclic aromatic hydrocarbons (PAHs) which are potentially carcinogenic or mutagenic. However, very few studies on biodegradation of three-ring fluorene were investigated as compared to other three-ring PAHs such as phenanthrene and anthracene. The aim of this work is to evaluate fluorene degradation by fungal strain isolated from the decayed wood in tropical rain forest, Malaysia, and examine the effectiveness of the strain for degrading fluorene in liquid culture supplemented with the nonionic surfactants. Detailed taxonomic studies identified the organisms as Pestalotiopsis species and designated as strain Pestalotiopsis sp. W15. In this study, fluorene was totally degraded by Pestalotiopsis sp. W15 after incubation for 23 days. Various analytical studies confirmed the biotransformation of fluorene by detection of two metabolites in the treated medium: indanone (R f 0.45; λ ₘₐₓ 240 and 290 nm; t R 7.1 min and m/z 132) and salicylic acid (λ ₘₐₓ 205, 235, 290 nm; t R 9.4 min and m/z 382). Based on these products, a probable pathway has been proposed for the degradation of fluorene by Pestalotiopsis sp. W15. None of the intermediates were identified as dead-end metabolites.

Since the 1990s, the emission of pollutants was reduced in a majority of Polish and developing country factories whereas the level of energy production was similar to that prior to the 1990s. The conifer investigated in this study has grown for many years under the stress of industrial pollution. Despite this, the trees are preserved, to a large extent, sensitive to the natural climatic factors. We present a complex analysis of the climatic (sunshine, temperature, precipitation, humidity, and wind circulation) and anthropogenic factors influencing the radial increment dynamics of Scots pine (Pinus sylvestris L.) growing in the vicinity of the combined heat and power station in Łaziska (Poland). We analyzed the spatiotemporal distribution of growth reductions, the depth of reduction with respect to the distance from the emitter, the relationship between tree growth and climate during the industry development period and during proecological strategy application . Samples of carbon isotopic composition in pine needles from 2012 to 2013 were additionally determined. Pines series of 3 positions indicate that they have a similar sensitivity to most climatic elements of the previous and given year, but there is also a different rhythm between the studied populations of incremental growth of pines. The causes of diversity are due to the different types of habitat (site types) and industrial pollution. The variation in carbon stable isotopic composition in pine needles was connected with an increase of CO₂.

This study assessed the suitability of passive sampler extracts for use with a GC-MS-database rapid screening technique for around 940 organic chemicals. Chemcatcher™ passive sampler systems containing either Empore™ SDB-XC or C18FF disks were deployed at 21 riverine sites in and near Melbourne, Victoria, Australia, for a period of 28 days during September–October 2008. Methanolic elution of the SDB-XC and C18FF disks produced an extract that, after evaporation and inversion into hexane, was compatible with the GC-MS-database method enabling over 30 chemicals to be observed. The sources of the non-agricultural chemicals are still unclear, but this study was conducted in a relatively dry season where total rainfall was approximately 40 % lower than the long-term mean for the catchment during the study period. Thus, the risks may be greater in wetter seasons, as greater quantities of chemicals are likely to reach waterways as the frequency, extent and intensity of surface run-off events increase. This study provides valuable information for policy and decision-makers, both in Australia and other regions of the world, in that passive sampling can be conveniently used prior to analysis by multi-residue techniques to produce data to assess the likely risks trace organic chemicals pose to aquatic ecosystems.

Calcium alginate beads entrapping a mixture of Fe(0) and nanosized magnetite (NMT) were prepared and evaluated for their capability to reduce nitrate in groundwater. Microscopic and spectroscopic analyses of the beads revealed that clusters of Fe(0)/NMT were entirely embedded in alginate polymer matrix containing a large number of carboxylic and hydroxyl functional groups. The extent of nitrate reduction increased with increasing content of Fe(0) and NMT in the beads, but there was a critical NMT mass limit relative to Fe(0) mass where no further increase in nitrate reduction occurred. The beads showed slower nitrate reduction kinetics than bare Fe(0)/NMT but had comparable capacity in overall nitrate removal. Nitrate reduction increased proportionally with an increase in bead dosage to give a maximum removal of 94.5 % at 37.5 g L⁻¹ in 48 h. Nitrate reduction with 50 g L⁻¹ beads achieved completion of two reduction cycles in 72 h to reduce 2.19 mM nitrate to less than 0.71 mM (10 mg-N L⁻¹) in each cycle. The overall results demonstrated that the beads developed in this study have a potential utility in remediation of nitrate in groundwater.

Copper hydrotalcites with and without adsorbed chlorophyllin exhibit a bactericidal effect that depends on the copper release and the basicity, which can be tuned through the chlorophyllin adsorption. The prepared solids performed well for the elimination of Escherichia coli, Enterobacter aerogenes, Salmonella enterica, and Staphylococcus aureus bacteria. The results showed that the copper-containing hydrotalcite with the adsorbed chlorophyllin is the most active material. Wastewaters from a metal industry were treated with these hybrid compounds, and the bactericidal effect was comparable with the results reported using more complex methods such as photocatalysis. Furthermore, one main advantage of these hybrid compounds is its low human toxicity compared with silver-containing materials.

As rice paddies are widespread sources of water pollution in the agricultural regions of the Asian monsoon area, a mechanistic understanding of nutrient loss from paddies is critical for water quality management. A 2-year experiment was conducted in a typical monsoon-affected rice field to improve our understanding of the impacts of rainfall and agricultural management practice on nitrogen (N) and phosphorus (P) loss. Samples of paddy drainage water were collected during rainfall events (n = 25) and analyzed for total N (T-N) and total P (T-P) concentrations. The impacts of rainfall (amount, duration, and intensity) and agricultural management practice (transplanting and fertilization) on the event mean concentration (EMC) and loss of nutrient were assessed using regression analyses. The results showed that T-N and T-P concentrations were affected by agricultural practice; meanwhile, loss of T-N and T-P was correlated with rainfall characteristics. Specifically, the EMC of T-N but T-P was negatively (p < 0.001) correlated with the number of days after agricultural practice in both years, which likely represents a decrease in nutrient availability in paddy water over time. Loss of T-N and T-P was positively (p < 0.01) correlated with rainfall amount, and this suggests that the rainfall-runoff process is a key driver of nutrient loss in the study area. Our results suggest that rainfall amount and days after transplanting need to be taken into account when estimating nutrient loss from rice paddies in monsoon regions.

Many studies have been conducted regarding the degradation of PAHs. One of the technologies that has been widely used is bioremediation due to its relatively low cost and greater efficiency for those compounds with structural complexity. Biotechnology has been used in several countries for many years and consists in the use of microorganisms (bacteria and fungi) to transform contaminants into inert substances, which is a result of the microbial activity from biochemical processes. This study aimed to develop a bioremediation methodology for the pollutant benzo[a]pyrene (B[a]P), which belongs to the group of PAHs. The potential use of a microbial consortium with Pseudomonas aeruginosa, Candida albicans, Aspergillus flavus, and Fusarium sp. for bioremediation was assessed. To confirm the pollutant reduction, quantifications of the samples were performed via gas chromatography–mass spectrometry (GC-MS). The contamination was prepared with a soil previously contaminated with B[a]P at the concentration of 3.74 mg kg⁻¹. The microbial consortium was added (16 μL g⁻¹), and samples were incubated for 42 days in an oven at 35 °C. The microbial growth curves showed representative differences between the samples in the presence and absence of the pollutant, demonstrating the possibility of bioremediation process. The final quantification of soil showed a mean concentration of 1.29 mg kg⁻¹, showed that 65.51 ± 0.95 % of the pollutant was degraded, which is an important and representative performance.

A study has been conducted to enhance fluoranthene degradation by combining biodegradation with hydrogen peroxide oxidation, as a chemical oxidant calcium peroxide has been used. The impacts of addition of calcium peroxide on microbial activity (phenol oxidase and acid phosphatase) as well as fluoranthene removal efficiency were investigated. It was observed that in the presence of calcium peroxide, the removal efficiency of fluoranthene on day 30 of the experiment was threefold higher as compared to a reference sample. It was found that the activity of phenol oxidase was stimulated on days 1, 7, and 14, by the presence of fluoranthene, whereas stimulation of the acid phosphatase activity in the samples of soil contaminated by fluoranthene was observed only after 14 days of the experiment. This may indicate that the induction period for this enzyme is longer compared with the induction period for phenol oxidase. The inhibition of the activity of both enzymes was observed in the presence of calcium peroxide.

Peatlands are often regarded as metal repositories, but under drought conditions may switch from sinks to sources of metals and contaminate downstream ecosystems. To evaluate whether the release of metals into soil solution in peatlands is predictable using simple, widely available soil parameters, six peatlands, with varying levels of metal contamination, including a previously limed peatland, were sampled around the Sudbury, Ontario, region, and were subjected to simulated drought. The simulated drought lowered soil water pH and dissolved organic carbon (DOC) concentrations, which is consistent with field observations. Metal partitioning (K d) values for Co, Mn, Ni, and Zn, with just one exception at one peatland, could be significantly predicted by just the pH of the soil water, although the strength of the relationship varied considerably among sites. The metal speciation model WHAM VII predicted that the free metal ion concentration of all metals tested, including Cu and Al, increased significantly with decreasing pH. At the same time, DOC-bound metal concentrations were predicted to decrease as DOC levels were lower, which for metals with strong organic matter affinities (Cu and Al) offset the increase in free metal ion concentration in soil solution following summer drought. Climate change forecasts for more frequent and sustained droughts may promote metal release from peatlands and increased mobilization to surface waters, and importantly, for some metals, the potential toxicity of the metals released from peatlands may increase to a greater extent than expected from increases in total metal concentrations because of decreased DOC following drought.

Measurement of the concentration of dissolved carbon dioxide in ground and surface aqueous environments is needed for a wide variety of scientific and industrial applications. These environments can be fresh, saline, or transitional in nature and can be hydrochemically complex. A next generation of sensors, like fiber-optic sensors, offer real-time, direct, distributed sensing of dissolved carbon dioxide and are an improvement over current technology for many applications; however, these sensors may be susceptible to signal disturbance when deployed in hydrochemically complex, natural environments. This complexity can best be characterized using hydrochemical modeling techniques. The modeling software, phreeqc 2.18, was used to conduct a comprehensive review to gain perspective on published data of natural water samples. Freshwater, saltwater, and transitional environments were characterized in terms of the distribution of carbonate and non-carbonate species present. Saline, transitional, and deep freshwater environments had the broadest range of carbonate distribution and species that may cross-interfere with sensor response. These data should be used to build complex laboratory test solutions that mimic the natural environment for use in sensor development. In some cases, specially engineered membranes may be required to mitigate the potentially cross-interfering effect of these ions.